<template>
  <view style="height: 100vh; display: flex; flex-direction: column;">
    <my-search @mySearchClick="gotoSearch"></my-search>
    <view class="scroll-container">
      <!-- 左侧滚动区域 -->
      <scroll-view class="left-scroll-view" scroll-y="true" :style="{height: wh}+'px'">
        <block v-for="(item,i) in cateList" :key="i">
          <view :class="['left-scroll-item', i === active ? 'active' : '']" @click="activeChanged(i)">{{item.cat_name}}
          </view>
        </block>
      </scroll-view>
      <!-- 右侧滚动区域 -->
      <scroll-view class="right-scroll-view" scroll-y="true" :style="{height: wh}+'px'" :scroll-top="scrollTop">
        <view class="cate-lv2" v-for="(item2,i2) in cateLevel2" :key="i2">
          <view class="cate-lv2-title">/{{item2.cat_name}}/</view>
          <view class="cate-lv3-list">
            <view class="cate-lv3-item" v-for="(item3,i3) in item2.children" :key="i3"
              @click="gotoGoodsList(item3.cat_id)">
              <image :src="item3.cat_icon" mode=""></image>
              <text>{{item3.cat_name}}</text>
            </view>
          </view>
        </view>
      </scroll-view>
    </view>
  </view>
</template>

<script>
  export default {
    data() {
      return {
        wh: 0, //滚动区域高度
        cateList: [], //分类数据列表
        active: 0,
        cateLevel2: [], //二级分类列表
        scrollTop: 0
      };
    },
    onLoad() {
      const {
        windowHeight
      } = uni.getSystemInfoSync()
      this.wh = windowHeight
      this.getCateList()
    },
    methods: {
      async getCateList() {
        const {
          data: res
        } = await uni.$http.get('/categories')
        if (res.meta.status !== 200) return uni.$ShowMsg()
        this.cateList = res.message
        this.cateLevel2 = res.message[0].children
      },
      activeChanged(i) {
        this.active = i
        // 为二级分类重新赋值
        this.cateLevel2 = this.cateList[i].children
        this.scrollTop = this.scrollTop === 0 ? 1 : 0
      },
      gotoGoodsList(cid) {
        uni.navigateTo({
          url: '/subpkg/goods_list/goods_list?cid=' + cid
        })
      },
      // 跳转到搜索页面
      gotoSearch() {
        uni.navigateTo({
          url: '/subpkg/my_search/my_search'
        })
      }
    }
  }
</script>

<style lang="scss">
  .scroll-container {
    display: flex;
    height: 100%;
    overflow: hidden;

    .left-scroll-view {
      width: 120px;

      .left-scroll-item {
        height: 60px;
        background-color: #f0f0f0;
        text-align: center;
        line-height: 60px;

        &.active {
          background-color: #fff;
          position: relative;

          &::before {
            content: ' ';
            display: block;
            width: 2px;
            height: 40px;
            background-color: red;
            position: absolute;
            top: 50%;
            left: 0;
            transform: translateY(-50%);
          }
        }
      }
    }

    .right-scroll-view {
      background-color: #fff;

      .cate-lv2-title {
        font-size: 12px;
        font-weight: bold;
        text-align: center;
        padding: 15px 0;
      }

      .cate-lv3-list {
        display: flex;
        flex-wrap: wrap;

        .cate-lv3-item {
          width: 33.3%;
          display: flex;
          flex-direction: column;
          align-items: center;
          margin-bottom: 10px;
        }

        image {
          width: 60px;
          height: 60px;
        }

        text {
          font-size: 12px;
        }
      }
    }

  }
</style>